E-Commuter with Bike trailer?

Hi everyone, this is the first time in my life I'm reaching out to a community, so please be nice to me.

So far I've been riding a classic commuting bike like the one in the picture (slim tires, straight handlebars, light and agile). Now that I have children, I'm looking for a comparable bike as an e-bike, but the "specialist stores" only ever offer heavy hardtails or ladies' bikes. The reason for this is probably my need for a motor + battery bike that can cope with the mountainous terrain on my doorstep and won't break down in the long term, even when carrying a bike trailer with two children.

Do you have any tips or tips on where/how I can get a relatively slim e-commuter that can regularly pull the bike trailer on normal but mountainous roads in everyday life?